1. Field of the Invention
The present invention relates to an automatic tire chain mechanism which moves the chains from a non-road contact position on a tire to the road contact position, and in particular, to an automatic tire chain which may be moved to its road contact position automatically by energy stored in a spring device.
2. Discussion of the Relevant Art
The art abounds with automatic chain devices and anti-skid devices for use on driver operated vehicles having a plurality of wheels with inflatable tires thereon. An anti-skid device is disclosed in U.S. Pat. No. 1,742,729 issued to J. A. Robinson on Jan. 7, 1930. The device disclosed therein utilized a chain physically mounted across grooves prepared in an automobile tire. The grooves are set at a predetermined depth, so that a chain having a thin portion and a thick portion can have the thin portion thereof concealed within the groove without contacting the road surface. By activation of the associated mechanism, the thin portion of the chain is used to pull the thicker chain into the grooves, thereby causing the chain to extend beyond the groove and come into contact with the road surface upon which the tire rests. The activation mechanism is relatively complicated and the chains are moved into the road contact position by a protruding member affixed to the chain which cooperates with a mechanism slideably mounted on the vehicle which extends outwardly and is adapted to cooperate with a protruding member.
Another retractable snow chain device is disclosed in U.S. Pat. No. 3,042,096 issued to G. K. Buergel et al on July 3, 1962. Therein is disclosed a system utilizing retractable snow chains. These chains in their retracted position are disposed within grooves provided on the tire. With the aid of a release mechanism mounted in the hub cap, the chain is released and by centrifugal force is permitted to rise above the groove and come into contact with the surface upon which the tire is rolling. A means for locking the chain in the road surface position is provided, as well as, means for activitating the release mechanism from the dashboard of the vehicle. The gearing mechanism required for proper operation is rather expensive and is mounted in the hub of the wheel.
Another automatic chain device is disclosed in U.S. Pat. No. 3,111,974 issued to C. M. Rice on Nov. 26, 1963. As disclosed therein, the tire chain is recessed in a groove provided in the tire tread. By activating a release mechanism mounted on the hub of the wheel, the chains are permitted to leave the groove and thus, come into contact with the surface of the tire. The activating mechanism includes a electrically controlled solenoid vacuum arrangement and gearing mounted in the hub of the wheel.
A further traction device is disclosed in U.S. Pat. No. 3,079,973 issued to J. J. Ziccardi on Mar. 5, 1963. As disclosed therein, the tire chains are disposed within the groove provided on the automobile tire. Activating a release mechanism permits the chain device by centrifugal force to pull out of the groove and move to the external surface of the tire so that it can come into contact with the road. Here again, the release mechanism is mounted in the hub of the wheel.
The instant invention overcomes the shortcomings found in the prior art by providing a simple inexpensive apparatus for moving a tire chain to the road contact surface of a tire from a position adjacent thereto with a minimum of components and without gearing required in the hub of the wheel.